How to match a bitmap and a checkbox (radiobutton) in a window ?

Hi,

      I draw a bitmap in a window and i want to use checkbox and radiobutton within this window. How can i do to match these two window controls background color with my bitmap ? In theory, i must initialize the background color of these controls to Transparent to prevent these backgrounds to overwrite the bitmap, so, the only things you can see are the text (checkbox & radiobutton) and the mark.
Must i use WM_CTLCOLOR, in which way ......

Thanks